数列是高中数学的重要内容之一,也是初等数学与高等数学的衔接点,因此在历年的高考试题中都占有较大的比重.而数列中的通项与求和又是数列中最基本也是最重要的问题之一,由于前n项和Sn也可视为数列的通项,所以数列是以通项为纲,数列问题,最终归结为对数列通项的研究,求解数列的通项就成了解决数列问题的突破口和关键点. Series is an important part of high school mathematics, mathematics and mathematics is also the convergence point of elementary mathematics, college entrance examination papers over the years have accounted for a large proportion of the sequence of items and summation is the most basic sequence is One of the most important problems is that since the first n terms and Sn can also be regarded as the general term of the series, the series is based on the general term, the sequence problem, which ultimately comes down to the study of the series of terms, It has become the breakthrough point and the key point for solving the series of questions.